[PATCH] bcm43xx: >1G and 64bit DMA support

This is a rewrite of the bcm43xx DMA engine. It adds support
for >1G of memory (for chips that support the extension bits)
and 64-bit DMA (for chips that support it).

Signed-off-by: Michael Buesch <mb@bu3sch.de>
Signed-off-by: John W. Linville <linville@tuxdriver.com>